World mission opportunities for Lutherans today

Mission responsibilities must be reconsidered to focus on the future as churches discuss merger and its eschatological dimensions. Renewal in other churches may be stimulated as they examine models suggested by merging churches. In spite of divergent views among Protestant and within the Lutheran family itself concerning an understanding of mission, there exists several convergent convictions. Mission is: inherent in the Gospel; evangelization as center; witness; forever; crossing of frontiers (geographical, economic, sociological, scientific, religious); for every country; responsibility of whole church; giving and receiving; facilitated by specialists; not triumphalistic; in need of more influence from Lutheran theological heritage; is God\u27s. Various strategies and cooperative efforts of engaging in mission should be planned after consideration of past commitments, experience and identity of church. A global perspective and two-way character should be maintained. God uses the church as an instrument for his mission

Clones with finitely many relative R-classes

For each clone C on a set A there is an associated equivalence relation analogous to Green's R-relation, which relates two operations on A iff each one is a substitution instance of the other using operations from C. We study the clones for which there are only finitely many relative R-classes.Comment: 41 pages; proofs improved, examples adde

Closed classes of functions, generalized constraints and clusters

Classes of functions of several variables on arbitrary non-empty domains that are closed under permutation of variables and addition of dummy variables are characterized in terms of generalized constraints, and hereby Hellerstein's Galois theory of functions and generalized constraints is extended to infinite domains. Furthermore, classes of operations on arbitrary non-empty domains that are closed under permutation of variables, addition of dummy variables and composition are characterized in terms of clusters, and a Galois connection is established between operations and clusters.Comment: 21 page

Special Issue Editorial: Youth, violence and equality: Perspectives on engaging youth toward social transformation

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Photo-absorption spectra of small hydrogenated silicon clusters using the time-dependent density functional theory

We present a systematic study of the photo-absorption spectra of various Si$_{n}$H$_{m}$ clusters (n=1-10, m=1-14) using the time-dependent density functional theory (TDDFT). The method uses a real-time, real-space implementation of TDDFT involving full propagation of the time dependent Kohn-Sham equations. Our results for SiH$_{4}$ and Si$_{2}$H$_{6}$ show good agreement with the earlier calculations and experimental data. We find that for small clusters (n<7) the photo-absorption spectrum is atomic-like while for the larger clusters it shows bulk-like behaviour. We study the photo-absorption spectra of silicon clusters as a function of hydrogenation. For single hydrogenation, we find that in general, the absorption optical gap decreases and as the number of silicon atoms increase the effect of a single hydrogen atom on the optical gap diminishes. For further hydrogenation the optical gap increases and for the fully hydrogenated clusters the optical gap is larger compared to corresponding pure silicon clusters.Comment: 6 pages, 5 figure

On the effect of variable identification on the essential arity of functions

We show that every function of several variables on a finite set of k elements with n>k essential variables has a variable identification minor with at least n-k essential variables. This is a generalization of a theorem of Salomaa on the essential variables of Boolean functions. We also strengthen Salomaa's theorem by characterizing all the Boolean functions f having a variable identification minor that has just one essential variable less than f.Comment: 10 page

Shoot growth and crown development: effect of crown position in three-dimensional simulations

Trees have been increasingly considered as modular organisms, with individual shoots forming autonomous units that respond semi-independently to their surrounding environment. However, there is evidence for fairly strict hormonal control of tree crown development. Studies on the hydraulic architecture of trees suggest a closer functional connection between shoots and crown development than is postulated by the theory of branch autonomy. We studied how shoot growth pattern influences growth and crown architecture in young Scots pine trees simulated by the LIGNUM model assuming that (a) the growth of a shoot mainly depends on its light climate and (b) the growth of a shoot is influenced by its position within the crown. We determined shoot position within the crown based on a recently developed vigor index. The vigor index compares the relative axis cross-sectional area from the base of the tree to each shoot and gives a value of 1 to the pathway of the greatest cross-sectional area. All other shoots attain values between 0 and 1 depending on their cross-sectional areas and the cross-sectional areas of the branches leading there from the main axis. The shoot light climate is characterized by annually intercepted photosynthetically active radiation. We compared the results from simulations (a) and (b) against an independent data set. The addition of a within-shoot position index (the vigor index) to our simulation (simulation b) resulted in a more realistic tree form than that obtained with simulation (a) alone. We discuss the functional significance of the results as well as the possibilities of using an index of shoot position in simulations of crown architecture

Individual tree biomass equations or biomass expansion factors for assessment of carbon stock changes in living biomass - A comparative study

AbstractSignatory countries to the United Nations Framework Convention on Climate Change (UNFCCC) and its supplementary Kyoto Protocol (KP) are obliged to report greenhouse gas emissions and removals. Changes in the carbon stock of living biomass should be reported using either the default or stock change methods of the Intergovernmental Panel on Climate Change (IPCC) under the Land Use, Land-Use Change and Forestry sector. Traditionally, volume estimates are used as a forestry measures. Changes in living biomass may be assessed by first estimating the change in the volume of stem wood and then converting this volume to whole tree biomass using biomass expansion factors (BEFs). However, this conversion is often non-trivial because the proportion of stem wood increases with tree size at the expense of branches, foliage, stump and roots. Therefore, BEFs typically vary over time and their use may result in biased estimates. The objective of this study was to evaluate differences between biomass estimates obtained using biomass equations and BEFs with particular focus on uncertainty analysis. Assuming that the development of tree fractions in different ways can be handled by individual biomass equations, BEFs for standing stock were shown to overestimate the biomass sink capacity (Sweden). Although estimates for BEFs derived for changes in stock were found to be unbiased, the estimated BEFs varied substantially over time (0.85–1.22ton CO2/m3). However, to some extent this variation may be due to random sampling errors rather than actual changes. The highest accuracy was obtained for estimates based on biomass equations for different tree fractions, applied to data from the Swedish National Forest Inventory using a permanent sample design (estimated change in stock 1990–2005: 420million tons CO2, with a standard error amounting to 26.7million tons CO2) Many countries have adopted such a design combined with the stock change method for reporting carbon stock changes under the UNFCCC/KP

Complexity Analysis of Iterative Basis Transformations Applied to Event-Based Signals

This paper introduces an event-based methodology to perform arbitrary linear basis transformations that encompass a broad range of practically important signal transforms, such as the discrete Fourier transform (DFT) and the discrete wavelet transform (DWT). We present a complexity analysis of the proposed method, and show that the amount of required multiply-and-accumulate operations is reduced in comparison to frame-based method in natural video sequences, when the required temporal resolution is high enough. Experimental results on natural video sequences acquired by the asynchronous time-based neuromorphic image sensor (ATIS) are provided to support the feasibility of the method, and to illustrate the gain in computation resources